package org.json;

/*
 Copyright (c) 2002 JSON.org

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.

 The Software shall be used for Good, not Evil.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */

import java.util.Iterator;

/**
 * This provides static methods to convert an XML text into a JSONObject,
 * and to covert a JSONObject into an XML text.
 * 
 * @author JSON.org
 * @version 2010-12-24
 */
public class XML {

	/** The Character '&'. */
	public static final Character	AMP		= new Character('&');

	/** The Character '''. */
	public static final Character	APOS	= new Character('\'');

	/** The Character '!'. */
	public static final Character	BANG	= new Character('!');

	/** The Character '='. */
	public static final Character	EQ		= new Character('=');

	/** The Character '>'. */
	public static final Character	GT		= new Character('>');

/** The Character '<'. */
	public static final Character	LT		= new Character('<');

	/** The Character '?'. */
	public static final Character	QUEST	= new Character('?');

	/** The Character '"'. */
	public static final Character	QUOT	= new Character('"');

	/** The Character '/'. */
	public static final Character	SLASH	= new Character('/');

	/**
	 * Replace special characters with XML escapes:
	 * 
	 * <pre>
	 * &amp; <small>(ampersand)</small> is replaced by &amp;amp;
	 * &lt; <small>(less than)</small> is replaced by &amp;lt;
	 * &gt; <small>(greater than)</small> is replaced by &amp;gt;
	 * &quot; <small>(double quote)</small> is replaced by &amp;quot;
	 * </pre>
	 * 
	 * @param string
	 *            The string to be escaped.
	 * @return The escaped string.
	 */
	public static String escape(final String string) {
		final StringBuffer sb = new StringBuffer();
		for (int i = 0, length = string.length(); i < length; i++) {
			final char c = string.charAt(i);
			switch (c) {
				case '&':
					sb.append("&amp;");
					break;
				case '<':
					sb.append("&lt;");
					break;
				case '>':
					sb.append("&gt;");
					break;
				case '"':
					sb.append("&quot;");
					break;
				default:
					sb.append(c);
			}
		}
		return sb.toString();
	}

	/**
	 * Throw an exception if the string contains whitespace.
	 * Whitespace is not allowed in tagNames and attributes.
	 * 
	 * @param string
	 * @throws JSONException
	 */
	public static void noSpace(final String string) throws JSONException {
		int i;
		final int length = string.length();
		if (length == 0) {
			throw new JSONException("Empty string.");
		}
		for (i = 0; i < length; i += 1) {
			if (Character.isWhitespace(string.charAt(i))) {
				throw new JSONException("'" + string + "' contains a space character.");
			}
		}
	}

	/**
	 * Scan the content following the named tag, attaching it to the context.
	 * 
	 * @param x
	 *            The XMLTokener containing the source string.
	 * @param context
	 *            The JSONObject that will include the new material.
	 * @param name
	 *            The tag name.
	 * @return true if the close tag is processed.
	 * @throws JSONException
	 */
	private static boolean parse(final XMLTokener x, final JSONObject context, final String name) throws JSONException {
		char c;
		int i;
		JSONObject jsonobject = null;
		String string;
		String tagName;
		Object token;

		// Test for and skip past these forms:
		// <!-- ... -->
		// <! ... >
		// <![ ... ]]>
		// <? ... ?>
		// Report errors for these forms:
		// <>
		// <=
		// <<

		token = x.nextToken();

		// <!

		if (token == XML.BANG) {
			c = x.next();
			if (c == '-') {
				if (x.next() == '-') {
					x.skipPast("-->");
					return false;
				}
				x.back();
			} else if (c == '[') {
				token = x.nextToken();
				if (token.equals("CDATA")) {
					if (x.next() == '[') {
						string = x.nextCDATA();
						if (string.length() > 0) {
							context.accumulate("content", string);
						}
						return false;
					}
				}
				throw x.syntaxError("Expected 'CDATA['");
			}
			i = 1;
			do {
				token = x.nextMeta();
				if (token == null) {
					throw x.syntaxError("Missing '>' after '<!'.");
				} else if (token == XML.LT) {
					i += 1;
				} else if (token == XML.GT) {
					i -= 1;
				}
			} while (i > 0);
			return false;
		} else if (token == XML.QUEST) {

			// <?

			x.skipPast("?>");
			return false;
		} else if (token == XML.SLASH) {

			// Close tag </

			token = x.nextToken();
			if (name == null) {
				throw x.syntaxError("Mismatched close tag " + token);
			}
			if (!token.equals(name)) {
				throw x.syntaxError("Mismatched " + name + " and " + token);
			}
			if (x.nextToken() != XML.GT) {
				throw x.syntaxError("Misshaped close tag");
			}
			return true;

		} else if (token instanceof Character) {
			throw x.syntaxError("Misshaped tag");

			// Open tag <

		} else {
			tagName = (String) token;
			token = null;
			jsonobject = new JSONObject();
			for (;;) {
				if (token == null) {
					token = x.nextToken();
				}

				// attribute = value

				if (token instanceof String) {
					string = (String) token;
					token = x.nextToken();
					if (token == XML.EQ) {
						token = x.nextToken();
						if (!(token instanceof String)) {
							throw x.syntaxError("Missing value");
						}
						jsonobject.accumulate(string, XML.stringToValue((String) token));
						token = null;
					} else {
						jsonobject.accumulate(string, "");
					}

					// Empty tag <.../>

				} else if (token == XML.SLASH) {
					if (x.nextToken() != XML.GT) {
						throw x.syntaxError("Misshaped tag");
					}
					if (jsonobject.length() > 0) {
						context.accumulate(tagName, jsonobject);
					} else {
						context.accumulate(tagName, "");
					}
					return false;

					// Content, between <...> and </...>

				} else if (token == XML.GT) {
					for (;;) {
						token = x.nextContent();
						if (token == null) {
							if (tagName != null) {
								throw x.syntaxError("Unclosed tag " + tagName);
							}
							return false;
						} else if (token instanceof String) {
							string = (String) token;
							if (string.length() > 0) {
								jsonobject.accumulate("content", XML.stringToValue(string));
							}

							// Nested element

						} else if (token == XML.LT) {
							if (XML.parse(x, jsonobject, tagName)) {
								if (jsonobject.length() == 0) {
									context.accumulate(tagName, "");
								} else if ((jsonobject.length() == 1) && (jsonobject.opt("content") != null)) {
									context.accumulate(tagName, jsonobject.opt("content"));
								} else {
									context.accumulate(tagName, jsonobject);
								}
								return false;
							}
						}
					}
				} else {
					throw x.syntaxError("Misshaped tag");
				}
			}
		}
	}

	/**
	 * Try to convert a string into a number, boolean, or null. If the string
	 * can't be converted, return the string. This is much less ambitious than
	 * JSONObject.stringToValue, especially because it does not attempt to
	 * convert plus forms, octal forms, hex forms, or E forms lacking decimal
	 * points.
	 * 
	 * @param string
	 *            A String.
	 * @return A simple JSON value.
	 */
	public static Object stringToValue(final String string) {
		if (string.equals("")) {
			return string;
		}
		if (string.equalsIgnoreCase("true")) {
			return Boolean.TRUE;
		}
		if (string.equalsIgnoreCase("false")) {
			return Boolean.FALSE;
		}
		if (string.equalsIgnoreCase("null")) {
			return JSONObject.NULL;
		}

		// If it might be a number, try converting it. If that doesn't work,
		// return the string.

		try {
			char initial = string.charAt(0);
			boolean negative = false;
			if (initial == '-') {
				initial = string.charAt(1);
				negative = true;
			}
			if ((initial == '0') && (string.charAt(negative ? 2 : 1) == '0')) {
				return string;
			}
			if (((initial >= '0') && (initial <= '9'))) {
				if (string.indexOf('.') >= 0) {
					return Double.valueOf(string);
				} else if ((string.indexOf('e') < 0) && (string.indexOf('E') < 0)) {
					final Long myLong = new Long(string);
					if (myLong.longValue() == myLong.intValue()) {
						return new Integer(myLong.intValue());
					} else {
						return myLong;
					}
				}
			}
		} catch (final Exception ignore) {
		}
		return string;
	}

	/**
	 * Convert a well-formed (but not necessarily valid) XML string into a
	 * JSONObject. Some information may be lost in this transformation
	 * because JSON is a data format and XML is a document format. XML uses
	 * elements, attributes, and content text, while JSON uses unordered
	 * collections of name/value pairs and arrays of values. JSON does not
	 * does not like to distinguish between elements and attributes.
	 * Sequences of similar elements are represented as JSONArrays. Content
	 * text may be placed in a "content" member. Comments, prologs, DTDs, and <code>&lt;[ [ ]]></code> are ignored.
	 * 
	 * @param string
	 *            The source string.
	 * @return A JSONObject containing the structured data from the XML string.
	 * @throws JSONException
	 */
	public static JSONObject toJSONObject(final String string) throws JSONException {
		final JSONObject jo = new JSONObject();
		final XMLTokener x = new XMLTokener(string);
		while (x.more() && x.skipPast("<")) {
			XML.parse(x, jo, null);
		}
		return jo;
	}

	/**
	 * Convert a JSONObject into a well-formed, element-normal XML string.
	 * 
	 * @param object
	 *            A JSONObject.
	 * @return A string.
	 * @throws JSONException
	 */
	public static String toString(final Object object) throws JSONException {
		return XML.toString(object, null);
	}

	/**
	 * Convert a JSONObject into a well-formed, element-normal XML string.
	 * 
	 * @param object
	 *            A JSONObject.
	 * @param tagName
	 *            The optional name of the enclosing tag.
	 * @return A string.
	 * @throws JSONException
	 */
	public static String toString(final Object object, final String tagName) throws JSONException {
		final StringBuffer sb = new StringBuffer();
		int i;
		JSONArray ja;
		JSONObject jo;
		String key;
		Iterator<String> keys;
		int length;
		String string;
		Object value;
		if (object instanceof JSONObject) {

			// Emit <tagName>

			if (tagName != null) {
				sb.append('<');
				sb.append(tagName);
				sb.append('>');
			}

			// Loop thru the keys.

			jo = (JSONObject) object;
			keys = jo.keys();
			while (keys.hasNext()) {
				key = keys.next().toString();
				value = jo.opt(key);
				if (value == null) {
					value = "";
				}
				if (value instanceof String) {
					string = (String) value;
				} else {
					string = null;
				}

				// Emit content in body

				if (key.equals("content")) {
					if (value instanceof JSONArray) {
						ja = (JSONArray) value;
						length = ja.length();
						for (i = 0; i < length; i += 1) {
							if (i > 0) {
								sb.append('\n');
							}
							sb.append(XML.escape(ja.get(i).toString()));
						}
					} else {
						sb.append(XML.escape(value.toString()));
					}

					// Emit an array of similar keys

				} else if (value instanceof JSONArray) {
					ja = (JSONArray) value;
					length = ja.length();
					for (i = 0; i < length; i += 1) {
						value = ja.get(i);
						if (value instanceof JSONArray) {
							sb.append('<');
							sb.append(key);
							sb.append('>');
							sb.append(XML.toString(value));
							sb.append("</");
							sb.append(key);
							sb.append('>');
						} else {
							sb.append(XML.toString(value, key));
						}
					}
				} else if (value.equals("")) {
					sb.append('<');
					sb.append(key);
					sb.append("/>");

					// Emit a new tag <k>

				} else {
					sb.append(XML.toString(value, key));
				}
			}
			if (tagName != null) {

				// Emit the </tagname> close tag

				sb.append("</");
				sb.append(tagName);
				sb.append('>');
			}
			return sb.toString();

			// XML does not have good support for arrays. If an array appears in a place
			// where XML is lacking, synthesize an <array> element.

		} else if (object instanceof JSONArray) {
			ja = (JSONArray) object;
			length = ja.length();
			for (i = 0; i < length; i += 1) {
				sb.append(XML.toString(ja.opt(i), tagName == null ? "array" : tagName));
			}
			return sb.toString();
		} else {
			string = (object == null) ? "null" : XML.escape(object.toString());
			return (tagName == null) ? "\"" + string + "\"" : (string.length() == 0) ? "<" + tagName + "/>" : "<"
					+ tagName + ">" + string + "</" + tagName + ">";
		}
	}
}